tdr.Read Function | R Table Operators | Teradata Vantage - 17.10 - tdr.Read - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - SQL External Routine Programming

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1147-171K
Language
English (United States)

Reads a row from an input stream. Returns one of the following codes:

Return Code Description
0 The operation was successful.
-1 The end of stream was reached.
-2 The table operator aborted.
-3 The input parameter has an invalid type.
-4 The input parameter has an invalid value.
-5 This function was called from the contract function.

Syntax

tdr.Read(  handle  )

Syntax Elements

handle
Parameter type: raw vector

The handle of the input stream returned by the tdr.Open function.

Usage Notes

Before you call this function, you must call the tdr.Open function to open the input stream. Then pass the handle returned from tdr.Open as an argument to this function.

This function is valid only if called from the table operator.

Example: Reading Rows From the Input Stream

This example opens an input stream and counts the number of rows successfully read from the input stream.

# Open the input stream.
library(tdr);
stream <- 0;
options <- 0;
direction <- "R";
inHandle <- tdr.Open(direction, stream, options);

# Read rows from the input stream.

nrrows <- 0;
while (tdr.Read(inHandle) == 0) {
  nrrows <- nrrows+1;
}